3School of Chemistry, College of Science, University of Tehran, Tehran, Iran

Abstract

Knoevenagel condensation between barbituric acid and aldehyde was investigated in the presence of sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) and resulted in the formation of arylidene and bis-arylidene barbiturates. Excellent yields and short reaction times are related to the high efficiency of SBA-Pr-SO3H that the reactions take place easily in its nano-pores. SBA-Pr-SO3H as an efficient heterogeneous nanoporous solid acid catalyst which was prepared by silica functionalization with (3-mercaptopropyl) trimethoxysilane followed by oxidation with H2O2, can be easily removed from the reaction mixture by simple filtration, and also recovered and reused without noticeable loss of reactivity.